:b13: - This looks like it protects the side, but it actually doesn't. Play on the 3rd line if you're trying to secure the territory.

O17 or O16 is actually better, though, as it's the natural continuation from the star stone once you have an extension to the middle of the other side. That is, you want to balance short extensions (knight jumps) and long extensions (5 space extensions). Since you're going for a moyo in the center, I think the short extension played high makes the most sense (O16), even though it leaves the corner unprotected. But either is playable I think.

, , are all smaller than finishing the bottom right corner. A 3-4 stone is unbalanced, and needs another move ASAP.

- Right idea, but the wrong side. Both white corners are pretty strong. But you have some neighboring strong-ish stones if you start this more towards the bottom. eg: C9 maybe, since it also aims at the B6 weakness. And then you can run out towards the center and find friendly stones pretty soon. Once your invasion is secure you can still aim at invading the top, since there's a region of 21 empty spaces (F17 to M17) with a hole in the roof. On the other hand white might be able to secure most of his moyo if you invade at C9, so I could be wrong

I've been told, though, that it's bad to have everything in a straight line because it's easier to cut.
I suppose I could play lower, but it's hard to resist the desire to grab just a little more.